A stock market correction is generally defined as short term price decline of 5% to 20%.The decline of May 2010 would qualify as "a market correction."
The S&P 500 fell from 1186.69 to 1089.41 during May 2010, a loss of 8.2%, and the biggest monthly loss since February 2009.
With dividends reinvested, 2009 returns for major stock market indices:
Dow Jones 22.68%
S & P 500 26.46%
Nasdaq 43.89%
Russell 2000 27.17%
Dow Jones Industrial Average +16.0%
Standard and Poors 500 +18.5%
NASDAQ +28.4%
Russell 2000 +17.6%
Dow Jones +7.6%
S&P 500 +11.9%
Nasdaq +22.6%
Russell 2000 +13.3%